Section 22A. Notwithstanding any provision of law or any regulation, ordinance or by-law to the contrary, a lodging house where lodgings are let to more than five but less then twenty persons may furnish individual cooking facilities for the preparation, serving, eating and storage of food; provided that no such facility shall be furnished in a room having an area of less than one hundred fifty square feet. Such facilities shall, in a single room, consist of a gas or electric plate, a refrigerator and hot and cold running water and in a unit consisting of two adjoining rooms shall consist of a gas or electric range, a sink with hot and cold running water, a refrigerator and storage area for food. Any facilities furnished under this section shall comply with the building code applicable thereto. This section shall apply only to cities and towns which accept its provisions.